here is a better link
http://www.classicparts.com/Chassis/products/224/
there should be zerk fittings on the end of the pins. if they haven't been geased in who knows how long and are seized or worn out they will make a noise, same as a broken shackle or pin. do not believe that they went to rubber bushings until 67. there could also be other reasons such as a brken centre bolt in the springs, frame, even bed bolts can cause noises. are you sure that is not just dried out old grease that you see instead of dry rot
sometimes a little grease will do wonders. I remeber , in 1975 I had a Hayes truck on logs out of Mackenzie,b.c.. I had a driver on and we were hauling nights off highway to save the roads at break up in March. diver complained that the truck was having difficulties steering around corners loaded* carrying about 105,000 lbs net with just a tandem axle trailer. I asked him if he was using that thing that was behind the seat. he said no what is it and I replied ; the grease gun and you should be greasing the frt bunk periodically and that will stop it from binding. that was the end of his driving career with me
ron